November 2008/Issue 25 think. what you can be

FIND OUT WHYON PAGE 23

SCUBA DRIVING

Gear up for the cars of the future

MOM’S BOOM! BOXWe pop an egg in the microwave

WHEELS ISSUE

Can you see this cover moving?

where anything round gets a turn

HOW TO • Build a go-kart • Survive a skid • Beat ice-cream brain freeze • Be an urban pirate

SMOOCH ALERTAre you allergic to kissing?

Cover.indd 1 10/28/08 10:09:15 AM

<<STA

RT HERE>>

SMART READS The world of wheels p 14 • Follow that car: futuristic transport p 18 •

Optical illusions p 23 • Backseat driving: teach mom how to drive

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ULARS Ed

’s note p 2 • Community of Hip: your news, your views p

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Brand Ambassadors: meet Ashleigh and Johannes p 6 • What’s n

ew in scienc

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Until you read this sentence, your

subconscious mind* controlled your breathing. But

now, because you’re thinking about it, your conscious mind has taken over.

• Deconstru

ction: GPS p 12 • Sci DIY: build – and pim

p – your own go-kart p 28 • Smart maths: d

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32 • Body sm

art: allergies p 34 • Brain busters: grey m

atter matters p 46 • Simply science: what c

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INTELLIGENT ENTERTAINM

ENT Be there – B

2: what’s hot p

36 • Music: Zebra & Giraffe get herd

p 39 • M

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• Games: why the world is your playground p 42 • Books: How to Fossilise Your Hamster

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<<THE E

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CHALLEN

GE Close your eyes (no peeking) and try to remember how many black rings surround this challenge …

If you got it right, you’ve just accessed your subconscious mind *.

Answer: 6 rings

contentsAeeek.indd 1 10/27/08 3:38:14 PM

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Winner: 2007 AdMag Custom Publisher of the Year

Editor Janna JosephArt Director Anton Pietersen

Managing Editor Nastassja HendricksJunior Writer Nicklaus Kruger

Copy Editor Sally RutherfordProofreader John Linnegar

Publisher Helena GaveraExecutive Editor Ami Kapilevich

Editorial Director Stefania JohnsonContributors Nikki Benatar, Ellen Cameron, Paul Carter, Erin Classen, Charleen Clarke, Simon Crundwell, Ambre

Nicolson, Linda Pretorius, Anthony Samboer, Mark van Dijk Educational Consultants Wordwise

BSQUARE COMMUNICATIONS EDITORIAL BOARDCommunications Manager Kate Evans

Marketing & Sponsorship Manager Lauren Terras<lauren@hip2b2.com>

HIP2B2 pioneered by Mark Shuttleworth

ADVERTISING & MARKETINGAdvertising Director Aileen O’ Brien

Sales Executives Nick Armstrong +27 (0)21 417 1188 Michael Daly (JHB) +27 (0)11 263 4804

PRODUCTION, CIRCULATION & SYNDICATIONProduction Manager Shirley Quinlan

Subscriptions John Pienaar +27 (0)21 417 1218Subscriptions Call Centre 0860 103 662

Syndication Manager Glynis Fobb Repro by New Media Repro

Printed by Paarl Print

Published on behalf of BSquare Communications by New Media Publishing (Pty) Ltd

+27 (0)21 417 1111 • <www.newmediapub.co.za>

New Business Development Martha Dimitriou +27 (0)21 417 1276

Creative Director Crispian Brown Production Director Lucrezia Wolfaardt

Digital Manager Helaine LindsayFinance Manager Mark Oaten

EXECUTIVE DIRECTORSManaging Director Bridget McCarney

Business Development Director John Psillos Editorial Director Irna van Zyl

All rights reserved. While precautions have been taken to ensure the accuracy of information, neither the editor, publisher nor New Media Publishing can

be held liable for any inaccuracies, injury or damages that may arise.

ABC 90 731

In the minute it’ll take you to read this page, about 250 babies will be born and around 100 people in the world will die. Your hair will grow approximately 278 nanometres, and over 300 000 000 cells in your body will be destroyed and replaced with new, healthy cells.

Our turning world is full of cycles, and fascinating things that go round. From the travelling wheels on your bike and Mom’s car to destructive hurricanes that tear through the air, there are cyclical things spinning all around you (for a whirlwind tour, turn to page 14).

Even here in our (very unround) HIP2B2 offi ce, a new cycle has begun, with Nevelia leaving her post as editor and me stepping into her funky shoes. But with every end comes a new beginning, so hi guys, and thanks for welcoming me onto the smartest magazine in our solar system.

So, as this minute ends and the next one begins, prepare for a head-spinning, page-turning read. Enjoy the last issue of HIP2B2 for 2008, and don’t forget to celebrate the new year in style.

JANNA

iWin If you’d like to

win an 80 GB Apple iPod Classic, with enough

space to store 20 000 tracks, SMS ‘iPod’ to 37555

before 1 January 2009 (R7,50 per SMS).

Chat room.indd 1 10/28/08 10:58:29 AM

Great idea, Aida! In fact, services like this do exist – check out <www.buster24.co.za> – but they don’t seem to be as readily available as you’re suggesting. Maybe it’s just a matter of

time. Meanwhile, think about how you’d ensure people don’t just walk off with the DVDs. – Janna

THEMBEKA NGCOBU

16, Kwadinabakubo Combined SchoolWe can change girls’ minds about doing science – that’s what has happened to me. My favourite wheel invention is the Renault. It’s my dream car and I’ll be very happy if I could have one one day.

GABIE PHUNGULA

16, Coastal CollegeMore girls should do science because it offers many interesting opportunities.I would love to make my community successful in this fi eld, and to teach science to homeless children.

We spoke to learners at the Sisters in Science event in KZN.

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DESHINI SRIKISSOON

15, Effi ngham Secondary SchoolToday I enjoyed coming second as a team in the competition!My favourite wheel invention is the car, because people have been able to carry science to areas that have never experienced it before.

NORMA DLADLA

17, Sithokozile Secondary School Today I enjoyed Colleen Aldous-Mycock’s talk about her career in science (she’s a geneticist).More girls should be interested in science, because there are so many job opportunities, especially for black women.

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YOU SAID IT

NTOKOZO MKHIZE

16, Kwadinabakubo Combined SchoolToday I learnt how important science is to us, the women in this country. I would love to be a famous South African scientist, and to help women understand science.

It’d be a great idea to invent a vending machine that dispenses DVDs. You could place them at petrol-station shops and people could take out movies at any time. You’d probably need to load a card with credit, so you couldn’t take out a movie without returning the previous one. – AIDA SOMWHALA, CAPE TOWN

Got a great invention or idea? Email <talk2us@hip2b2.com>.

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FORUM

5

6 0 k P a of pressure is exerted by penguins when expelling faeces, which is four times as much as that exerted by humans in the same situation.

1 9 4 1 is the year the Batmobile made its fi rst appearance. It wasn’t the cool black version we know, but just a red car with a bat hood ornament. Like all other Batmobiles, though, it was amazingly fast, proving that super-rich vigilante playboy geniuses get to have all the fun.

0 spiders live in Antarctica.

Over 2 5 0 0 left-handed people are killed every year by using products made for right-handed people.

4 1 2 , 2 8 k m / h is the maximum speed attained by the fastest mass-produced, street-legal car, the SSC Ultimate Aero TT.

Hey what’s up? Scientifi cally, the sky

is up! L.O.L … My name is Philile Zulu from

Richards Bay, and I’m in Grade 11 at John

Ross College. I’m proud to say I’m part of our

school’s Science Club, and it’s great because

we get the HIP2B2 magazines and there are

many experiments we are going to do.

I have to say I love your magazine. It has

really improved my general knowledge – now I

know why my tummy rumbles and why I smile!

I also try to watch your show every Monday, but

recently I couldn’t because I had lots of tests

(Grade 11 is no joke). At our school, there are

many students who love science, and it would

be great if you could visit our school some time.

Please send a shout out to the Science Club

and Mrs Naidoo. Hope 2 see u soon!

Hey Philile … Respect for joining the Science Club and

thanks for the letter. Please send us a photo of you

guys doing one of our experiments, and we’ll publish

it in a future issue :). ’Til then, stay smart. – Janna

ON THE SMS CHAT LINE

I luvd the murder mystery story in the last issue of HIP2B2. Thanx for a gr8 magazine! – CANDICE NICOLSON

Can you tell me why the sky is blue? – SAMANTHA CHABABlue light’s wavelength is about the same size as an oxygen atom, so it’s scattered by the gases in the atmosphere. See <www.sky-watch.com/articles/skyblue.html> for more info. – Janna

SMS ‘HIPCOM’ followed by your thoughts to 34978 (R2 per SMS), or comment free of charge on our MOBISITE at <mobi.hip2b2.com>.

EMAIL <talk2us@hip2b2.com> or <hip2b2@newmediapub.co.za>.

WRITE TO HIP2B2, PO Box 440, Green Point 8051.

PHOTOGRAPH the world of science around you and upload your pics at <www.hip2b2.com>.

CHAT Click to the Forum section at <www.hip2b2.com>.

Had a brainwave? Got something on your mind? We want to know …

T A L K T O U S

YOU SMSED

SENT IN BY Simon van Wyk, Grade 10.WHY THIS PIC? The other day, I noticed that my second toes are longer than my fi rst toes. After a little investigative googling, I found out this is a genetic trait called Morton’s toe, and that I share my funny feet with about 10% of the population.

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Northcliff High School, Grade 11

ASHLEIGH’S PROJECT IDEA My project uses leftover heat energy from nuclear-reactor plants to desalinate sea water and generate more electrical energy.AIM Irritation with load shedding has made me want to solve our current power crisis.

I would love to help people in the medical fi eld some day, by doing something like prosthetics design

or dietetics, but I also love art! I’m juggling many options right now – there are so many opportunities out there!I wish I could calculate the precise speed of my tennis shots, but I leave the maths for when I’m watching TV broadcasts of Federer doing his thing on court. I may be a little accident-prone. On our Grade 11 camp, I had so many embarrassing moments (which will remain within our dormitory, thanks). Maths is vital in art. If you have incorrect proportions or your perspective is wrong, your art looks more Jackson Pollock than Michelangelo! All the great artists, like Da Vinci, were keen mathematicians too. I love spending time in nature. I recently visited Ngwenya Lodge on the border of the Kruger Park, and we saw the Big Five from our chalet patio!If I had a million bucks, I’d buy part of a game park and build a hostel/school on the property for teenagers who want to excel at school and launch themselves into their chosen fi eld. I believe other teenagers who work hard and do well should be given the opportunities I’ve been given. Did you know: one percent of the static on your TV when you change channels is a relic of the Big Bang?

BRAND AMBASSADORS

Meet two HIP2B2 Ambassadors with their eyes on the ball and their feet on the ground.

Stellenbosch High School, Grade 10

JOHANNES’S PROJECT IDEA My project is to research the online interests of South African teenagers, by creating a social bookmarking system. To get an idea of it, click to <www.yoop.co.za>. AIM I love creating websites, so I tried to combine this with a research component, while also rendering a free service to SA teenagers.

I’d like to combine my interest in websites with the business world and start a web-design agency. I’m trying to gain as much experience as possible for this, and I’m also

running a business called Novo Web Solutions. I like fl ight simulators, and I’ve spent all of 10 seconds in the pilot’s seat of a real Boeing 767. At this stage, fl ying is more of a hobby for me, but I’ll defi nitely get a personal pilot’s licence one day.I still like public speaking, though standing in front of a whole school with nothing to say was very embarrassing (long story). Right now, I’m focusing on

other activities, but I would like to get into debating … I’ll just think twice before doing unprepared speeches again!One website I’d defi nitely recommend is iGoogle, a service from Google that allows you to customise your home page with relevant content from all over the Web – very useful if you want to have the latest news updates, email notifi cations and so on all on one page when you log on.If I could know the answer to any question, I’d want to know what my purpose in life is, or what it’s going to be.

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Spotlight on ASHLEIGH and JOHANNES

ASHLEIGH WATERSON

For more on the HIP2B2 Brand Ambassadors and their project ideas and activities, check out <www.hip2b2.com>.

Want to learn a bit more about Johannes? Visit his website at <http://johannesjonker.com>.

JOHANNES JONKER

brand ambass.indd 1 10/27/08 3:49:33 PM

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ARE YOU HIP ENOUGH?

Good grades and accomplishments in these fi elds are an advantage, but a larger-than-life personality is vitally important. Only learners in grades 8, 9 and 10 may apply.

Come on Limpopo, Mpumalanga, Free State and Northern Cape – we

need Hip stars from your provinces.

Smart. Young. Hip. The search is on for HIP2B2 Brand Ambassadors.

DO YOU HAVE WHAT IT TAKES?

• A passion for science, maths, invention, entrepreneurship or computers;

• a commitment to challenge and showing your peers just how cool and crucial these subjects really are;

• excellent people and communication skills; • imagination and a positive attitude; and• strong leadership qualities. If you have what it takes to represent HIP2B2 click to <www.hip2b2.com> to

download the application form. Applications close on Tuesday, 25 November.

Meet Mark

ShuttleworthAppear on TV

Boost your CV

Have you seen these guys before? They’re

the HIP2B2 Brand Ambassadors, and they’ve appeared in magazines, on the Web, on the radio and on TV throughout 2008. And now, they

might be looking for you …

brand ambassad.indd 1 10/27/08 3:50:47 PM

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CIB The Centre of Excellence for Invasion Biology conducts research, development and training in biodiversity science.

To fi nd out more about the CIB, or about the research presented here, click to <http://academic.sun.ac.za/cib>.

W H AT ’ S N E W I N S C I E N C E ?SCI FILES

A WORLD IN EVERY BITE

Scientists need sustenance, too. And sometimes a simple bite to eat can turn into food for thought. During a discussion over a Big Mac, fries and a cup of coffee, researchers at the Centre of Excellence for Invasion Biology (CIB) began to ponder the evolutionary relatedness (or phylogenetics) of the plant components of their meal.

Humans consume a varied diet but, although we eat many plant species, most research shows that all the plants come from a few closely related families. To test this, the researchers applied phylogenetic techniques to their seemingly all-American meal.

THE VERDICTThe fries (potatoes) came from South America. The mustard was from India, the onions and wheat from the Middle East, and the coffee from Ethiopia. In total, the meal contained 20 species from 12 plant families, from all eight global centres of cultivated plant diversity!

THINKING IT THROUGHThe researchers reckon that the remarkable breadth of the human diet may be a result of our massive geographic range, diverse food-collection methods and ability to process normally inedible items. (Anyone for a cup of roasted, ground, dissolved coffee beans?)

THE BARE NECESSITIES

Jellyfi sh have no heart, blood, gills, lungs … or even brain!

CLOVER FACT Foam and function

The frothy milk on top of a cappuccino isn’t just for show – it seals the surface of your coffee and keeps it hot for longer.

SCIENCE ON THE BEACH Jellyfi sh are unearthly creatures, glooping around in sightless silence. But don’t be fooled; they’re taking over our coasts. Scientists aren’t sure why their numbers are increasing, but they do know we’re somehow to blame. Be it climate change, overfi shing or eutrophication*, we seem to have disturbed their ecosystems.

Jellyfi sh blooms can be quite a problem. They can block intake and cooling systems for power plants (the last thing we need, with our load-shedding troubles), and they can interfere with fi shing operations. Then there’s the matter of swimmers being stung by them, which isn’t that great for coastal tourism.

Enter an army of scientists from the University of the Western Cape, who have launched an extensive research programme to fi gure out why these guys are multiplying, and what we can do to stop them. But they need your help …

JOIN SA JELLY WATCHYou don’t need to be an expert or carry complicated instruments. You just need to hang out by the sea, enjoy the sun and make a few observations. For info, click to <http://sajellywatch.uwc.ac.za>.

*Eutrophication occurs when there are excessive nutrients in a body of water, usually caused by run-off (waste, fertilisers, and so on) from land, which stimulates excessive plant growth and reduces dissolved oxygen in the water.

Whats new in science.indd 1 10/27/08 3:53:33 PM

that happens from about 80 km or higher above the Earth’s surface.

Space science is a rapidly emerging fi eld in South Africa. The government is establishing the South African Space Agency, and our own unique microsatellite, SumbandilaSAT, will be launched soon. This satellite will take pictures of southern Africa to help with research, planning and management in fi elds such as agriculture, the fi shing industry, water resources and urban planning, and to deal with losses caused by fi res, oil spills and other disasters.

You’re 002, the world’s top investigative space agent, and you have work to do …

How is Earth observed from space?Earth-observation satellites can study the atmosphere (meteorological observation) or the sea, land and even oceanic winds.

Greetings, Space Agent 002. Your top-secret space mission is about to commence. The location: above and beyond Earth’s atmosphere. The mission: infi ltrate the world of space science, and fi nd out its activities. If they’re good for our planet, learn the secrets and report back. If the world of space science is not on our side … well, you know what to do. But fi rst, here’s some background info to get you up to speed.

WHAT IS SPACE SCIENCE? Space science refers to any scientifi c fi eld that studies events in space or space fl ight. This normally includes anything

ADVERTORIAL

“SAASTA is a business unit of the National Research Foundation (NRF)

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smart, innovative or wacky

Scientists at the University of California, Berkeley, are one step closer to developing materials that could make invisibility possible. Using artifi cially

engineered metamaterials* with a negative refractive index (which causes light to be diffracted in really strange ways) to redirect light around objects, they’ve managed to bend electromagnetic waves of a certain frequency without generating shadows or distortions.

These negative index materials aren’t useful only for invisibility: they also allow light to be focused on a very small point. This could allow us to illuminate individual molecules or even individual atoms. The implications for molecular biology, chemistry and quantum physics are incredible.

Don’t get too excited, though: plenty of work needs to be done before we end up with our own invisibility cloaks. To learn more about

metamaterials and their capabilities, click to <www.metamaterials.net>.

NOW YOU SEE ME ...

Polypterus senegalus, the grey bichir, is a carnivorous fi sh that guards the bottom of African shallow waters and estuaries. It has survived nearly 100 million years of constant biting attacks from predators and rivals, largely thanks to a certain natural advantage: each scale on its body is layered in such a way that the pressure of a crunching bite is defl ected. The design also forces cracks to run in a circle around the penetration site, dissipating

energy that may otherwise rupture scales. But why leave such a good idea to

wallow around underwater? A team at MIT has fi gured out how these scales work, and is now applying what they’ve learnt to the development of new human body armour.

*Metamaterials are man-made materials such as ceramic, Tefl on or cybercomposite, which are structured to get around the limitations of natural materials.

LOW-TECH MOMENTReinventing the wheel

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The pizza wheel has earned an honoured position in modern society as one of the easiest and least messy ways to carve manageable slices out of your cheesy delight. But the wheel’s days could be numbered now that a new bit of kitchen technology has arrived: pizza scissors. The scissors cut slices to your desired size and also serve as handy lifters, so you don’t have to worry about slices breaking apart on the way to your plate or mouth.

BIG PIZZA

The world’s largest pizza was made in 1990 in the Norwood Hypermarket, Joburg. With a

diameter of 37,4 m (the length of about fi ve elephants), it used 500 kg of fl our, 800 kg

of cheese and 900 kg of tomato purée. South Africa also holds the record for the furthest pizza delivery ever made: Bernard Jordaan of Butler’s Pizza in Cape Town delivered a pizza 11 042 km to Sydney, Australia in 2001.

FISHY ARMOUR

smart technology1.indd 2 10/28/08 9:23:55 AM

11

Just over 100 years ago, the fi rst heavier-than-air machine made its maiden fl ight, staying airborne for a cool 15 seconds. Now we have planes that can fl y more than 25 000 times as long, with no pilots and using only the power of the sun.

Qinetiq’s Zephyr is a HALE UAV (high-altitude long-endurance unmanned aerial vehicle). It’s powered by lithium-sulphur batteries that are recharged during the day by extremely thin solar panels on its wings. It weighs only about 30 kg, and has a highly effi cient engine. The Zephyr fl ew for 82 hours and 37 minutes, nearly three times as long as the previous offi cial UAV world record.

With technology like this already in the air, it’s surely just a matter of time before we’re all literally riding on sunbeams.

Everybody knows the military always has the coolest technology. M2E Power has been developing motion-powered

electronics for the US military, but it’s fi nally turned its attention to more important things: cellphone batteries.

M2E Power has developed a new external charger that’s powered by kinetic energy. In other words, it charges your cellphone as you walk. Eventually these chargers may replace batteries altogether, but for now, they mean you’ll never again have to worry about your battery running out when there are no electrical outlets in sight.

CHARGE AS YOU GO

DID YOU KNOW?

The fi rst cellphone call was made on 3 April 1973 by Martin Cooper of Motorola. He called his company’s rival, AT&T’s Bell Labs, on a phone that weighed almost 1 kg.

FAST FACT

On average, light from the Sun takes 253 minutes to reach the outermost planet, Uranus, a distance of 4,55 billion kilometres (or roughly 3 million times the distance between Cape Town and Joburg).

BEAM ME UP

SMART TECHNOLOGY

RAT OR ROBOT

Gordon is a bit of a rat. He’s also a bit of a robot.

It can’t be easy. Designed by a team at the UK’s University of

Reading, Gordon has a brain made of living nervous tissue, cultured from rat neurons. His brain is also equipped with electrodes that pick up the electric signals

generated by the cells, and his movement is controlled by these signals. There’s no outside control, either from a human or a computer.

Researchers are now tackling the secrets of memory formation as they try to get Gordon to learn new responses, by repeatedly making specifi c signals whenever he makes certain movements. Gordon may also help scientists to understand brain-affecting diseases such as Alzheimer’s and Parkinson’s.

smart technology1.indd 3 10/28/08 9:25:05 AM

we take it apartDECONSTRUCTION THE INNER WORKINGS

Global Positioning System (GPS) technology has made life a lot easier. Instead of fumbling with fold-out maps, you type your destination into this device and voice prompts guide you there. But how does it work?

Just like in the old days when explorers navigated using the stars, the GPS takes its orders from the sky. More specifi cally, from about 24 satellites that quietly orbit the earth. A GPS receiver (like this Garmin Nuvi) picks up signals transmitted by these satellites through its antenna (1). By carefully timing the signals sent by at least three satellites, it can calculate its precise 2-D position (latitude and longitude). With data from four or more satellites, the receiver can even determine its 3-D position (latitude, longitude and altitude).

The device can also calculate information like speed, bearing, track, trip distance and distance to destination. These calculations take place via processors mounted on the printed circuit board (PCB) (2). The resulting information is displayed on the liquid crystal display (LCD) screen (3), which is made out of antiglare material that maintains good visibility even in bright sunlight (that’s one:nil to modern travellers vs the early explorers, who could only navigate at night). And with its full-colour LCD touch screen (4), the Nuvi has done away with buttons.

Adding more maps is easy; you can load them via an SD memory card (5), or through your computer using the USB interface (6). The GPS is powered by an internal lithium-ion battery (7), which can be recharged via the car’s cigarette lighter. TE

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FAST FACT

You think you’re speeding? GPS satellites orbit the earth at about 11 270 km/h.

For optimum reception the antenna (1) should be parallel

to the surface of the earth

Printed circuit board (PCB) (2)

Microphone

Rear power connector tabs Earphone jack

Speaker

USB interface for loading data (6)

SD memory-card expansion slot (5)

Power button

Connector for external antenna

decon.indd 2 10/27/08 4:00:19 PM

13

DECONSTRUCTION: GPS

DID YOU KNOW?

GPS was developed by the US Department of Defense. The name ‘Garmin’ is made up of the fi rst three letters of the company founders’ names: Gary Burrell and Min Kao.

OUR FAVOURITE BITSThe latest generation GPS receiver

comes with bonus features like an integrated MP3 player or picture viewer, but the advent of Bluetooth technology means it can also be used

as a hands-free kit for your cellphone.

SHOCK HORRORBe careful not to rely too heavily on your GPS. It may be

smart, but it won’t be able to warn you if a dog has decided it likes your lane. Until the satellites fi gure that one out, it’s still essential to keep your eyes on the road. Earlier this year in Seattle, a bus driver ripped a large chunk off his bus’s roof after blindly following a GPS and

trying to go under a footbridge that turned out to be a tad too low. Five people

(and his ego) were injured.

The rechargeable lithium-ion battery (7) lasts four to eight hours

Antenna casings Antenna (1)

Connector for external antenna

Ratchet for adjusting antenna angle

Reset button

Back casingSpeaker

Backlit colour LCD screen (3)

Fingertip touch-screen interface (4)

Microphone connector to PCB

Front casing

LCD back plate

decon.indd 3 10/27/08 4:00:44 PM

14

You don’t have to ride a bicycle – or a car, motorbike, tank, skateboard or even rollerblades – to know that mechanised transport is based on the wheel. Even ships (which use steering wheels) and aeroplanes (which use wheel-like turbine engines … and wheels to taxi along runways and for landing) get their get-up-and-go from the wheel.

Sometimes you can’t even see the wheels. The SEGWAY PT is a two-wheeled electric vehicle that looks something like a lawnmower but acts like a self-balancing scooter, with a top speed of 20 km/h. It balances using on-board computers, motors and hidden gyroscopes. If you lean too far forward, the gyroscopes will turn and correct themselves so that you (and your Segway PT) don’t fall fl at on your face.

Think wheels and you think cars, but think again. From tornadoes to the WHAT GOES WHEELS THAT MOVE

GOING SOMEWHERE

FAST FACT

The only person who managed to fall off the Segway PT was American President George Bush, but perhaps he wouldn’t have found it so hard if he’d just turned it on fi rst!

The same guy who invented the Segway PT, American entrepreneur Dean Kamen, also invented the iBOT – a six-wheeled wheelchair that can ‘walk’ up and down stairs by rotating its two sets of wheels around each other. What’s smarter than that? Well, how about a wheel that can move in any direction? The MECANUM WHEEL – invented in 1973 by Swedish designer Bengt Ilon – has rollers attached to its wheels at 45° angles, allowing the wheels to move forward, backwards and sideways.

Segway PT

iBOT

Mecanum wheel

For more about the Mecanum wheel and how it works, click to <www.nationmaster.com/encyclopedia/Mecanum-wheel>.

world of wheels.indd 2 10/28/08 8:37:50 AM

WHEELS

15

AROUND ...GOING NOWHERE

WHEELS THAT TURN BUT DON’T TRAVEL

While many wheels (like the wheels on your bicycle) need power to turn, some actually generate power themselves. The WATER WHEEL uses fl owing water to push its blades or buckets along, generating hydropower, which can then be used to produce electricity or turn other attached wheels – like a millstone that grinds wheat into fl our.

One wheel is specially designed not to go anywhere. The GYROSCOPE is a device that measures and maintains orientation, adjusting its rings to keep its axle pointing in the same direction. This enables anything connected to it to balance in exactly the same position.

Cars and trains can take you places, but if you want a new perspective, you need a giant wheel. The FERRIS WHEEL is an amusement park ride, but it’s also sometimes used as an observation tower. Every day it goes round and round but it never really gets anywhere, kind of like a HAMSTER WHEEL , but without a giant hamster in the middle.

The London Eye in London (go fi gure) is a whopping 135-metre-tall Ferris wheel … but it’s not the tallest in the world. The world’s biggest Ferris wheel is the Singapore Flyer, which has a diameter of 150 metres and – because it’s built above a three-storey building – a total height of 165 metres.

DID YOU KNOW? Work is underway on the world’s biggest-ever Ferris wheel, the Great Beijing Wheel. When completed at the end of 2009, it’ll stand at a dizzying 208 metres.

Crafters over the centuries have also used stationary spinning wheels to create many day-to-day items. Potters spin clay on a POTTER’S WHEEL , using their hands to turn the clay into rounded objects like mugs, jars and bowls. Before the advent of modern machinery, textile workers used SPINNING WHEELS to turn thread or yarn into fabrics … or, as in the fairy tale Sleeping Beauty, to put pretty princesses to sleep.

To win your very own handheld gyroscope, turn to page 28. For more information on gyroscopes and how they work, click to <www.gyroscopes.org>.

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Potter’s wheel

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Spinning wheel

Water wheel

tiny tails on bacteria, the world is full of wheels.

world of wheels.indd 3 10/28/08 8:39:18 AM

16

Not all wheels are good. In medieval philosophy, the goddess of Fate would spin her

WHEEL OF FORTUNE (Rota Fortunae), randomly changing people’s fates. Today, similar wheels of

chance have the same effect on many gamblers.

Some destructive weather patterns also act like wheels, sending cyclic winds crashing into populated areas. Here’s how to tell one whirling wind from the next:

CYCLONE A violent storm created when low atmospheric pressure causes inward spiralling winds, called whirlwinds. These resemble massive (and really gusty) cloud ‘cones’.TROPICAL CYCLONE A cyclone that forms in the tropics (between the equator and the tropics of Capricorn and Cancer).TYPHOON A severe tropical cyclone that forms specifi cally in the western Pacifi c and Indian oceans. It lasts only a few hours and spins due to the collision of associated winds.HURRICANE A severe tropical cyclone that forms in the western Atlantic Ocean and the eastern side of the Pacifi c Ocean (that is, east of the International Date Line). It’s larger, longer-lasting and more destructive than a typhoon, and the direction it spins is affected by the turning of the Earth (which is why hurricanes spin clockwise in the southern hemisphere and anticlockwise in the northern hemisphere). TORNADO While cyclones tend to happen over sea, tornadoes

happen over land, with a rotating column of air connecting the surface of the Earth to a giant cumulonimbus cloud. Tornadoes

create winds of about 100 km/h, sometimes even more!

You know how your bath water spirals down the plughole? There are WHIRLPOOLS like that in nature, but instead of

being created by gravity, they’re created by tidal fl ow. Most are small and harmless, but sometimes they form a VORTEX ,

which is like the funnel of a tornado, but in water.

DID YOU KNOW? The world’s most powerful whirlpool – known to

locals as Moskstraumen or the maelstrom – is found off the Lofoten archipelago in northeastern Norway.

It has a top speed of approximately 27,8 km/h.

WHEELS OF DESTRUCTION

GOING CRAZY

The most destructive vortex (whirling

mass) is a BLACK HOLE , which is created when the core of a supernova*

collapses. A black hole has a gravitational fi eld so strong that it sucks in gas and supercompresses it into the densest

substance in the known universe, and nothing – not even light or the guys

from Prison Break – can escape. *A supernova is a massive

exploding star.

Whirlpool

Tornado

Black hole

world of wheels.indd 4 10/29/08 8:30:30 AM

17

GOING GLOBAL

WHEELS AROUND THE WORLD

Money may make the world go round, but no two economists can agree on exactly how

that happens. There are many, many theories doing the rounds about ECONOMIC CYCLES

– and here’s the most basic one: an economy experiences high demands, low unemployment and

good growth, but then that growth slows down to a point at which demand declines and unemployment

rises. Then, much to the relief of just about everyone, the economy recovers and the cycle starts again.

It’s not just economies that go round and round: the colour spectrum can also be shown as a COLOUR WHEEL . Colours

are arranged in a circle according to the wavelength of light, with the primary colours (red, yellow and blue)

positioned 120° apart, and the secondary colours (orange, green and purple) positioned between the primaries.

The whole world, really, is made up of wheels. Cartographers (mapmakers) divide the Earth into lines of LATITUDE (west to east, starting at the equator) and LONGITUDE (north to south, starting at the Greenwich Meridian). Each line forms an imaginary wheel around the Earth, represented by degrees.

DID YOU KNOW? Nobody lives at the point where the 0° lines of latitude and longitude intersect. It’s a spot in the Atlantic Ocean, about 1 000 kilometres west of Gabon!

The Earth spins around the Sun in an ORBIT that is elliptical (slightly oval). According to Kepler’s Laws (named

after 17th-century astronomer, Johannes Kepler):1 the orbit of every planet is an ellipse, with the Sun

at one of the foci (or focal points);2 a line joining a planet and the Sun covers equal

areas in equal intervals of time (the planet slows down as length of the line increases); and

3 the squares of the orbital periods of planets are directly proportional to the cubes of the

semi-major axis of the orbits. In other words, for any planet in our solar system, the longer its

orbit (ie the further it is from the Sun) the slower the planet moves.

THE WORLD’S smallest WHEEL

So who invented the wheel? As it turns out, bacteria were the fi rst to come up with the

concept. The smallest wheel you’ll fi nd in nature is located in the tail section of a bacterial cell. Here’s how it works: the tail-like structure, or FLAGELLUM , that

powers the cell (and by ‘powers’ we mean ‘moves it forward’) is driven by a tiny, tiny rotary engine. This engine (which is made up of protein) is located at the point where the

fl agellum anchors itself to the inner cell membrane. That rotor sends protons across the membrane and starts turning. The bacterial fl agellum can rotate at about 17 000 rpm … but

it usually cruises along at a slow(ish) 1 000 rpm. In case you’re wondering, a sperm cell has a

eukaryotic fl agellum, which is more like a tail. So, no: your circle of life didn’t start

out with a wheel!

Flagellum

Colour wheel

WHEELS

world of wheels.indd 5 10/28/08 8:43:25 AM

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may seem like a gazillion years ago, but cars really aren’t as old as they seem. In fact, when compared to the Earth they drive on, they’d be bounced out of any self-respecting museum.

Need proof? Just google Ford Model T, the fi rst car produced on an assembly line instead of being crafted by hand. Released only 100 years ago, the car didn’t offer new buyers much choice: as founder Henry Ford famously put it, ‘They can have any colour, as long as it’s black.’

Today things are different. First of all, there are now hundreds of cars and colours to choose from. Secondly – and much more coolly – manufacturers are creating increasingly way-out concept cars*.

Generally, these contraptions look pretty radical. They also come with many smart features, based on today’s top-two VIP issues: the environment and safety.

*concept cars are vehicles that indicate their manufacturer’s future plans. Some become production models, while others never see the light of day.

POND, JAMES POND

Anyone can feel like 007 in the new, amphibious sQuba concept car, designed by Swiss fi rm Rinspeed and capable of diving to about 10 metres.

Powered on land by an electric motor and propelled underwater by two jet drives,

this truly convertible convertible provides passengers/on-board divers with

breathing air from a self-contained on-board system.

Hyundai QarmaQ

sQuba concept car

Wicked, wonderful or just plain weird – car manufacturers have some surprises up their designer sleeves.

smart wheels2.indd 2 10/28/08 8:15:43 AM

SMART WHEELS

19

Take, for instance, the QarmaQ, developed by Hyundai and GE Plastics and boasting 30-plus environmentally progressive technologies. One of the most impressive is a body made out of around 900 recycled PET (polyethylene terephthalate) bottles. (A car made out of cooldrink bottles? What next? One that runs on mango juice?)

Turning to safety, the QarmaQ has an ‘elastic front’: the body panels are designed to work together with energy-absorbing systems on the underside of these panels to manage and dissipate the force of a collision.

Another car that smiles on the environment is Citroën’s C-Cactus hybrid. Produced predominantly from recycled or recyclable materials, it’s not very thirsty (just like the plant it was named after).In fact, it sips only about three litres of diesel per 100 km, with CO2 emissions of only 78 g/km (compared to over 300 for a Hummer). The designers deliberately made it as light and cost-effective as possible, removing anything nonessential, such as the dashboard.

The ignition key is also cool: it’s a portable MP3 player with a touch screen. When plugged into the steering wheel (only the outer rim turns), the car recognises the ‘key’ and can be started by pushing a button.

For of the Citroën C-Cactus’ stylish design, click to <www.citroenet.org.uk/prototypes/c-cactus/c-cactus.html>.

In Grease (1978), John Travolta and his T-Bird gang sported hairstyles as greased up as their car. In the famous ‘Greased Lightning’ scene, their junk-yard jalopy gets the benefi t of an extreme makeover.

They say VW Beetles go forever, but this one’s taking it a bit too far. Herbie got his fi rst big break in The Love Bug in 1967. Almost 40 years later, he’s still going strong, hooking up with Lindsay Lohan in Herbie: Fully Loaded.

‘Groovy’ used to be the kind of world only your mom or your gran would use. That was before Austin Powers came along and made words like ‘groovy’ and cars like his Union Jack-painted 1967 ‘Shaguar’ E-Type not just cool, but groovy (baby).

If you want to make a styling entrance, follow 007’s lead and arrive in a super-smooth Aston Martin DBS. Driven by the controversially blond Daniel Craig in Casino Royale (2006), it was almost as distracting as Vesper’s knockout purple dress or Craig’s blue eyes.

<< ROLLING ON CAMERA How ’bout a round of applause for Hollywood’s four-wheeled fi lm stars?

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Peugeot’s Seed car takes some of these concepts even further. Powered by

electricity provided by solar panels, this car

has no windows! Instead, it has a wraparound LCD that shows the surroundings to the driver.

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SMART WHEELS

20

FUEL FOR THOUGHT There are many ways to power a car. These are some of the most widely used fuels.

Petrol or diesel: these traditional oil-based fuels are still the most popular. Petrol is usually slightly cheaper, but it emits around 10% more CO2.

Liquefi ed petroleum gas (LPG): used overseas; it’s possible to convert a regular car to run on LPG.

Then there are some concept cars that veer totally off the beaten (or tarred) track. Take, for instance, the Renault Reinastella prototype fl ying car.

Created in 1992 and named after a luxury car produced between 1929 and 1933, the French car-maker unveiled it on 2 April the same year (they deliberately avoided 1 April, worrying that Parisians

Compressed natural gas (CNG): this can be used in cars, but is more widely used in trucks and buses. Only used overseas.

Hydrogen: it’s being used in some production cars (like BMW’s 7 Series),

but is not yet available in SA.Biofuels: many different

biofuels are available, made from anything from cooking oil to sugar or maize, but the technology hasn’t caught on here yet.

Ethanol and methanol: alternatives to petrol in internal-combustion engines, these fuels are also not yet used in South Africa, though they are used overseas. Ethanol is popular in Brazil.

Electricity: available overseas, electric cars use a battery and an electric motor. A major snag is their limited range.

Hybrid cars: these use an electric motor and a petrol engine (à la Toyota’s Prius). But watch this space: Lexus launches its diesel hybrid here this year.

would think it was an Avril Poisson or April Fools’ joke). But this was no joke – it was the designers’ honest prediction of what a car would look like in 2038. (Phew, we’ve still got 30 years to get it right.)

WHO

NEEDS A DRIVER?

General Motors has unveiled the Chevrolet Tahoe ‘Boss’, a driverless

car that eliminates the greatest cause of accidents: driver error. Using radar and GPS mapping, the car recognises road geometry and perceives obstacles on the road. It then uses intelligent algorithms and computer

software to fi gure out where to drive. It recently competed in a rally and

beat other driverless cars. More signifi cantly, it thumped cars

with drivers too!

Even more way-out is the 16th BMW Art Car, unveiled earlier this year. It was designed by Danish-Icelandic artist Olafur Eliasson, who took a hydrogen-powered BMW racing-car prototype known as the H2R and then – we kid you not – coated it in ice! Covered with fragile, sparkly layers, the car required some 2 000 litres of water to make. The snag? It has to be stored in a freezer, so don’t expect to see it in sunny SA any time soon.

Many concept cars include futuristic features. Take the Nissan Pivo 2, for

example. It has a cabin that rotates 360º, which means you need never reverse and it’s always a breeze to park. Plus, the Pivo 2’s wheels turn 90º, so you can drive the car sideways as well as forward.

Blind spots are reduced, thanks to the incorporation of

screens mounted inside the car that display

the surrounding area. Despite its teensy size (it’s only

2,7 metres long), it can accommodate three

people (the driver in front and two passengers at the back).

Nissan Pivo 2

For more recent developments in fl ying-car technology, click to <www.msnbc.msn.com/id/20535980>.

smart wheels2.indd 4 10/28/08 8:18:18 AM

We have reason to believe that space scientists aim to help the world. Here’s some information on the tools they use, and how they appear to be using them wisely.

SATELLITE STRUCTURE An Earth-observation satellite consists of:• OBSERVATION INSTRUMENT Acts like

a camera, taking ‘pictures’ (observation data) and sending them back to a data-recording and telemetry unit. (Telemetry lets you measure the Earth from far away.)

• TELEMETRY SUBSYSTEM Sends the data it observes as well as information about on-board units to the ground station.

• COMMAND SUBSYSTEM Almost works like your brain, sending commands to the rest of the units on the satellite.

• DATA STORAGE SUBSYSTEM Stores housekeeping data of subsystems.

• NAVIGATION SUBSYSTEM Produces data about the satellite’s position in space.

• ATTITUDE CONTROL SUBSYSTEM Tells the ground station what the satellite’s direction is compared to that of Earth.

• PROPULSION SUBSYSTEM Provides the power to change the fl ight path (orbit) and attitude of the satellite.

• POWER SUBSYSTEM Supplies the electric power necessary for operation.

• THERMAL CONTROL SUBSYSTEM Keeps the temperatures of on-board units within set ranges.

• PROCESSING SUBSYSTEM Controls the entire satellite’s operations.

HOW DOES IT BENEFIT US? Through satellite technology, we can get important data about human activities. We can also analyse the Earth as a global system of connected natural processes. The data we receive from the satellites increases our knowledge of Earth science and helps decision-makers address challenges.

A great advantage of space-based observation is that it can cover a large area. Typical uses for satellite data include agricultural monitoring, predicting where human health problems may arise (for example, changes in rainfall aff ect the spread of ticks and mosquitoes), security (disaster management), land-use change (for example, if the soil is being eroded by human activities), solid-earth hazards (such as earthquakes and tsunamis), climate and weather changes, and water resources.

These things may infl uence the way we live and work, and even our ability to survive on Earth!

LINKS TO MILITARY, GEOGRAPHY AND AGRICULTURE Earth observation from space is closely linked to military applications. For example, the GPS started out as a military tool but is now highly useful to the general public.

Remote sensing uses instruments that can detect radiation at a specifi ed frequency such as infrared, visible or ultraviolet. For example, the advanced visible and near infrared radiometer (AVNIR) is used for observing land and coastal zones in visible and near-infrared regions. The data from AVNIR tells us about desertifi cation, the destruction rate of tropical forests and pollution of coastal zones.

Data from AVNIR and other sensors on Earth-observing satellites can tell us about irrigated landscape mapping or soil conditions.

For example, a researcher can use this information to fi nd out if a certain soil type, given a certain amount of water at a certain time of year, produces more or fewer crops than another area that received water at a diff erent time of the year.

“SAASTA is a business unit of the National Research Foundation (NRF)

ADVERTORIAL

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23

OPTICAL ILLUSIONSIL

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SEEING THINGS Think your eyes never lie? Take a look at these pictures and tell us if you think they're moving or not … The images below may seem to move, but they’re actually totally stationary. To see the 'movement', relax your eyes and try not to focus on any specifi c area.

HOW DO THEY WORK?

Optical illusions work because you see with your mind as well as your eyes. The image that enters your eye is processed before you

THE ILLUSIONIST

Meet Akiyoshi Kitaoka, Japanese psychology professor and maker of these illusions.

How do you make an illusion rotate?The order of colours used for illusory motion is black dark grey white light grey black; a circle will rotate in the direction of this sequence. In the Rotating Snakes illusion (on the front cover), blue corresponds to dark grey while yellow corresponds to light grey, and the colours are repeatedly arranged. Colour is not essential, though; luminance is enough, but some colour combinations seem to enhance the effect.

What was the fi rst illusion you ever made? I guess it was the chequered illusion. (Check it out at <www.psy.ritsumei.ac.jp/~akitaoka/corner.pdf>.)

Why can some people see certain illusions better than others? A visual illusion is a psychological phenomenon, which inevitably depends on each individual. So do not worry if you can't see the movement. I confess that even I do not see some illusions.

Still seeing straight? Try the illusions on the HIP2B2 TV show, Monday, 12 January '09 on SABC 2 at 16:30.

‘see’ it, fi rst by nerve cells in your retina and then by your brain. When the object you’re viewing contains extreme contrast (as these do), this system discards confl icting signals and fi lls in gaps to make sense of the image, creating the illusion. Which is cool when you’re combating visual disturbances, but not so cool (or maybe cooler, depending on how you look at it) with images like these.

Turn the page for an eye-boggling poster to pull out and paste on your wall.

Some illusions can cause dizziness or even epileptic fi ts (triggered when your brain can’t handle the confl icting information from your two eyes). If you feel sick, immediately cover one eye with your hand and turn to page 26. Don’t close your eyes – it’ll just make it worse.

WARNING!

TRICK OR TREAT?

For an unexplained but amazing optical illusion, click to <http://talespinshalom.blogspot.com/2007/02/rotating-illusion-pink-eye-trick.html>.

optical illusions.indd 1 10/27/08 4:02:30 PM

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Before power steering, puny drivers suffered in silence. Now, most systems use hydraulic pressure to minimise

effort and allow the steering wheel to correspond with the position of the wheels. Neat and easy.

Electrohydraulic power-steering systems also use hydraulic pressure, but it’s provided by a pump

driven by an electric motor, instead of being engine-driven. Electric power-steering systems

don’t use hydraulics at all; sensors detect the motion of the steering column, and a computer

regulates the amount of assistance provided.

PARENTAL GUIDANCE Make sure dad knows what to do in a spin: steer smoothly in the same direction as the

spin to help the tyres grip the road; then, once the skidding is over, accelerate slightly and steer in the direction he wants to go.

Tyres are the only part of your car that touch the ground (unless you’re doing it wrong), so they need to have enough grip to keep you on the road. To do this, they come with a pattern of deep grooves and smaller slits, called tread.

The grooves allow better water channelling from the front of the tyre to the rear on wet surfaces, so there’s less chance of sliding. The ridges provide a greater surface area in contact with the road (they distort inwards slightly as you drive). Little dimples in the tread prevent heat distortion, and the edges of the tyre maintain contact with the road while cornering. PARENTAL GUIDANCE Tread must be at least 1,6 mm deep.

GROOVY TYRES

Special tyre-tread patterns exist for specifi c purposes. Snow tyres have extra-deep grooves that bite into snow and mud, while some also come with metal studs that dig into the ice for extra grip.

POWER STEERING

TYRE TREAD

BACKSEAT It’s almost as

if they know you’re there. Sometimes you pull up to a red light and it immediately turns green. Other

times (and this feels sadistic), you’ll wait forever for the light to change when there’s no-one else around for miles. So what gives?

Actually, it’s got nothing to do with luck or mechanical moods. In large cities, where traffi c’s

too constant to regulate on a case-by-case basis, traffi c lights operate on standard

timers based on calculations and computerised traffi c models.

In regions where traffi c’s quieter, it’s easier

to customise traffi c fl ow. The most common way to sense approaching cars

is the inductive loop, a circuit that detects a change in inductance (caused by the presence of metal). The loops form a rectangle in the road.

PARENTAL GUIDANCE Late for soccer practice? Tell mom to stop in the centre of the rectangle, to make sure the light should turn green soon. If she

misses it entirely (though that’s really hard to do), you’re in for a loooong wait.

FAST FACT Emergency use only

Emergency vehicles may override traffi c signals to help them save the day in record time. To do this, the vehicle must be fi tted with a signal device, and the light must have a receptor.

TRAFFIC-LIGHT TIMING

BY NICKLAUS KRUGER • ILLUSTRATIONS: ANTON PIETERSEN

traffic.indd 2 10/27/08 4:06:33 PM

These are areas you can’t see while looking through the windscreen or in your mirrors. Side blind spots are caused by the angle of your mirrors – there’s always something they just can’t cover (see the blue triangles in the diagram on the right).

You can check your blind spots by turning your head. Of course, this’ll cause a blind spot in front, but you can’t win them all … PARENTAL GUIDANCE Make sure mom isn’t hogging someone’s blindspot by teaching her this simple rule: if she can’t see the other driver’s face in his mirror, he can’t see her.

Antilock Braking Systems (ABS to friends) prevent wheels from locking

while braking. Most of these systems have an Electronic Control Unit (ECU) with one sensor

for every wheel, and two or more hydraulic valves in the vehicle brake circuit. When the ECU senses some wheels are

rotating signifi cantly slower than others (because you’ve slammed on the brakes), it reduces the braking force on those wheels by

repeatedly locking and releasing them.

This doesn’t mean you can dodge through traffi c like a ninja, but it does prevent skidding. The downside? On loose surfaces like

snow or gravel, ABS brakes increase braking distances.

PARENTAL GUIDANCE If mom’s car doesn’t have ABS, tell her to buy a new one – it could save her (and your) life. Because

the wheels aren’t able to lock, she will always be able to steer the car, even if it gets into a skid.

A traffi c jam is never fun, especially when the other lanes seem to be going faster than you. But how do you know if they’re really ahead, and when should you tell dad to change lanes?

STAY WHERE YOU ARE TIME FOR A CHANGE

• You could be going just as fast as the other lanes on average, but only noticing them when they’re faster than you.

• If the road has three or more lanes, you probably won’t pick the fastest one anyway.

• Changing lanes causes hundreds of thousands of accidents a year, so it’s often safer to stay put.

• You could be going just as slowly as you think – any driver is more likely to be in the slow lane because there are more cars in that lane.

• If there are three or more lanes, the odds are you’re not in the fastest one.

• Less time on the road means less chance of an accident, so if it’s really faster, go for it.

BLIND SPOTS

ABS BRAKESTRAFFIC JAMS

27

DRIVING ROAD SCIENCE

FAST AND FURIOUS

While some studies have shown that ABS reduces the risk of crashing, others found no difference at all. This is thought to be caused by a phenomenon called risk compensation – drivers respond to the safety of ABS by driving more aggressively.

BLIND SPOT DIAGRAM

Forward fi eld of vision

Rear-view mirror fi eld of vision

Side mirror fi eld of vision

I CAN SEE CLEARLY NOWThe ability to treat every situation – including your own – as if you were a random observer isn’t only important on the road. It could also answer some of biology and cosmology’s most interesting questions. To fi nd out how, click to <www.anthropic-principle.com/primer.html>.

Don’t just sit and stare out the window. It’s time to teach mom and dad the rules of the road.

traffic.indd 3traffic.indd 3 10/29/08 8:58:26 AM10/29/08 8:58:26 AM

28

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YOU’LL NEED • tape measure • wood: 2 x 40 mm x 100 mm x 40 mm planks for the seat; 2 x 40 mm x 100 mm x 40 mm planks for the sides; 1 x 40 mm x 100 mm x 100 mm plank for the back rest; 1 x 1 200 mm x 100 mm x 40 mm plank for the steering column; 2 x 500 mm x 70 mm x 70 mm pieces for the wheel axles (these must be sturdy enough to bear your weight and to withstand the insertion of screws) • saw • sandpaper (optional) • nails, heavy-duty screws, nuts, bolts and washers • 4 wheels (old pram wheels will do) • drill • wood glue • hammer • rope

DO IT YOUR WAY

Of course, your go-kart doesn’t have to match our size specifi cations. Feel free to play around with the measurements – whatever lets you ride comfortably should be fi ne, as long as you build in

Looking for the thrill of the open road … or hill? Check this out.

MAKE YOUR OWN

GO-KART

enough axle support. To reduce the costs of the raw materials, team up with friends and build the go-kart together.

WHAT TO DO

1 Measure the wood and saw the pieces to your desired fi t. Optional: sand the pieces down for a smooth fi nish (and to avoid splinters in your butt).

2 Insert a washer over four long, heavy-duty screws, and then push each wheel onto a screw.

2 Drill a hole into each side of your front and rear axles.

3 Pour wood glue into each hole, and then quickly hammer in the screws (with the wheels attached).

4 Nail the steering column to the rear axle.5 Nail the seat to the rear axle.

CHALLENGE: PIMP YOUR RIDE Give your go-kart a makeover – go

bling, go bold or go blindingly bright – then upload a pic at <www.hip2B2.com>. At the end of 2008 we’ll choose the winning

team (maximum four learners per team), and each winner will receive a futuristic Powerball gyroscope, a HIP2B2 backpack

and a HIP2B2 phone tone device that’ll give your landline an

MP3 ringtone.

6 Nail the side and rear pieces to the seat.7 Drill a hole through the middle of the

front axle and a matching hole through the front of the steering column.

8 Drop a nut through the hole and bolt it down on both ends.

9 Knot the rope around both ends of the front axle, and hit the road!

BETTER BUILDING

For simple, step-by-step instructions, click to <www.kartbuilding.net/Wooden_Go-Kart_Plans/index.html>.

sasol.indd 2 10/27/08 4:08:10 PM

ADVERTORIAL

Reaching new frontiersSasol is more than just a fuel company – it uses science and technology to create magic and improve the lives of others. Did you know that this innovative company was founded out of the wacky idea of turning coal into petrol? Today, more than 50 years later, it is an established market leader in the energy industry.

JOBS FOR AFRICAAre mathematics and science your favourite subjects? The Sasol bursary scheme is especially geared towards learners who have a passion for these disciplines.

ACHIEVE YOUR DREAMSSasol offers exceptional opportunities to talented people – your curiosity and enthusiasm can help you achieve your dreams and reach new frontiers.

BRILLIANT BURSARIES Sasol offers bursaries for full-time university studies in BSc Engineering, BSc and BCom. Click to <www.sasolbursaries.com> or call 0860 106 235 to fi nd out more.

Choose a great career in science CIVIL ENGINEERING Civil engineers handle the design, construction and maintenance of the built environment (and also the natural environment as it affects and is affected by human development). Roads, buildings, bridges and dams are the work of civil engineers, who also ensure buildings are safe, traffi c fl ows well, sewage is drained and waste is managed. Civil engineers work closely with architects and city planners, as well as with other engineers and scientists.

This career will suit you if you have an aptitude for maths, an appreciation for the science behind everyday things, and lots of patience. It also helps if you don’t mind getting your hands dirty.

WHAT DO YOU NEED TO STUDY THIS? To register to study civil engineering at a tertiary institution in 2009, you’ll need to write an admissions exam. You’ll also need to score at least a four in mathematics and physics. Many South African universities offer four-year BSc degrees in Civil Engineering, and some technical institutions offer a three-year diploma as well. You can study for a fi fth year to earn an Honours degree or a Master’s in Technology.

sasol.indd 3 10/27/08 4:09:21 PM

WHAT‘S COOKING? You use one almost every day, but do you really know what your

microwave is capable of?

METHOD We removed the rotating dish and placed an egg at the centre of the oven, then heated it on full power.

WHAT HAPPENED? Boom! Water in the egg was heated to over 100 ºC, forming steam that built up until the shell cracked (spectacularly) under pressure.

>> EQUIPMENT: an egg

EGG BOMB EXPANDING SOAP

>> EQUIPMENT: a bar of soap

METHOD We placed a simple bar of soap in the centre of the microwave and turned it on at full power.

WHAT HAPPENED? The soap expanded into a huge, polystyrene-like blob of goo. Soap contains water, fats and air, and can expand to fi ve times its original size!

WIRELESS LIGHT BULB

>> EQUIPMENT: a clear light bulb

METHOD We placed a clear light bulb in the centre of the microwave and turned it on at full power.

WHAT HAPPENED? The fi lament glowed as it trapped the microwave energy, and the argon in the glass let off a ‘plasma glow’ as it became ionised.

30

CAUTION! DO NOT TRY THIS AT HOME

BEFORE

AFTER AFTER

BEFORE

DURING

BEFORE

Microwave.indd 2 10/27/08 4:11:04 PM

HOME LAB

31

1 The magnetron tube emits electrons (negatively charged particles) that spiral around in a powerful magnetic fi eld, causing them to emit microwaves.

2 Molecules in the material align themselves with the fi eld.

3 The fi eld alternates rapidly, making the molecules vibrate, and the friction generated as they rub together heats the material. This works best in water-based liquids, because the molecules are dipolar (they have a negative end and a positive end, so they respond better to the magnetic fi eld) and they are more mobile.

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>> EQUIPMENT: a cork, cocktail sticks

METHOD We pushed cocktail sticks into a cork and placed it centrally in the oven. We then lit the ends of the sticks and switched the microwave on.

WHAT HAPPENED? The fl ame fl ared sporadically. The sticks produced carbon soot as they burned, which absorbed the energy and released it in bursts.

GLOWING WOOL

>> EQUIPMENT: a roll of steel wool

METHOD We took a roll of steel wool and placed a bundle in the centre of the microwave, then switched the oven on at full power.

WHAT HAPPENED? The wool glowed like bonfi re embers. The electrical charge absorbed by the metal concentrated at the jagged edges, causing fi res.

FAST FACT Hot chocolate

Microwaves were born in 1946, when engineer Percy Spencer was experimenting with a magnetron tube and noticed that the chocolate in his pocket had melted. After further tests with popcorn and his very own egg bomb, he placed the magnetron tube and some food inside a metal box. The microwaves refl ected off the walls and created the world’s fi rst instant meal.

MagnetronHOW A MICROWAVE WORKS

DURING

BEFORE BEFORE

DURING

AFTER CLOVER FACT

What happens when you place a stick of butter in the microwave? It melts, of course. The melting point of butter (the point at which it becomes runny) is only around 32–35 ºC. That’s lower than human body temperature – you could melt a block of butter just by holding it in your hand for a while.

Microwave.indd 3 10/29/08 8:33:08 AM

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FRICTION – FRIEND OR FOEFRICTION is an unfortunate consequence of motion. It’s always there, and most of the time it’s a nuisance. It’s the reason space capsules heat up to 1 500 °C upon re-entry into the atmosphere, and it’s the prankster that causes engines without oil for lubrication and water-cooling to seize.

But friction isn’t always the bad guy. Without its effect between the road and our tyres, cars wouldn’t be able to drive, brake and turn corners. In fact, without friction we wouldn’t even be able to walk!

So what is friction and how does it work? In short, it’s a force that always acts against us, pulling or pushing in the opposite direction to the way we want to move (no wonder it’s a little unpopular).

The size of the force is measured in newtons (N) and depends on the type of surface and the weight of the object being moved (provided it’s on a horizontal surface). We can write this as an equation: friction = μ x mass x 10, where μ is the coeffi cient of friction.

The coeffi cient of friction basically measures how ‘rough’ a surface is.

Here are some examples:

SURFACES μ

Steel ice skate on ice 0,03

A rubber tyre on dry asphalt 0,50

A rubber tyre on wet asphalt 0,25

Between the joints in the human body 0,01

Wood on concrete 0,62

Tefl on on Tefl on 0,04

THINK AND WINDid you know friction is the only reason early man could make fi re? All he needed was two sticks, a pile of twigs and a few well-timed breaths. If you know how friction fuelled the fi rst man-made fi res, email <win@hip2b2.com> with your name, grade, school and answer, and you could win a stationery set.Smart Maths sponsored by

force is with you in a skid:• don’t slam on the brakes;• change to a lower gear and accelerate

slightly to ‘regrip’ the road; and• don’t fi ght the friction – let the

wheels turn towards the skid to regain their grip on the road.Of course, most modern cars now

come with technology to prevent you

SUM IT UP1 Thando plays netball. If she has a mass

of 60 kg and wears shoes with rubber soles, what is the maximum friction force between her shoes and the playing surface? (Use the coeffi cient of friction for rubber and asphalt from the table.)

friction = μ × mass × 10 = 0,5 × 60 × 10 = 300 N

2 If David has to use 350 N of force to pull a 50 kg bag of fertiliser across a concrete fl oor, calculate the coeffi cient of friction between the bag and the fl oor.

friction = μ × mass × 10 350 = μ × 50 × 10 μ = = 0,7

How to survive a skid Have you noticed that it’s harder to get something to move than to keep it moving? That’s because there are two types of friction – static and kinetic.

When a car drives normally, its wheels make contact with the road through static friction. When a car gets into a skid, it slides across the road and has less grip, thanks to kinetic friction. To ensure the

from skidding in the fi rst place: antilock braking systems (ABS) (see page 27), four-wheel drive, traction control, electronic stability control (ESC) and electronic brake stabilisation (EBS), to name a few.

To see a cool skid, click to <www.youtube.com/watch?v=CLUTWdhI6Bg>.

Don’t let a useful force rub you up the wrong way.

smart maths2.indd 1 10/28/08 8:10:10 AM

There are many potential dangers and challenges associated with space science, as you will gather from the information below …

‘SPY’ SATELLITES To a certain extent, the technology used in Earth-observation satellites can monitor the activities of human beings, for example, the building of roads.

Communication satellites could be used to monitor radio and microwave-based telecommunications.

However, some ‘spy’ satellites gather data that could be used to monitor cloud cover or the rate of desertifi cation and land degradation. In fact, in the USA the space agency NASA works with a number of partners, including their Department of Homeland Security.

Research, satellites and computer models can provide data that can respond to any threat to the USA’s infrastructure. Although satellites are traditionally used

for mapping and disaster relief, they can also be used for law enforcement or border security. The problem is that some people see this as an intrusion of their privacy.

GLOBAL SECURITY – COUNTRY LEGISLATIONS AROUND OCCUPYING SPACE Thanks to humankind’s natural phobia of Big Brother watching us 24/7, several countries, notably Australia, the USA, Sweden, Russia, Canada, the UK and Israel, have developed legislation to guide and regulate their space activities.

Here in South Africa, outer space and its applications are increasingly interesting conversation topics. We are currently developing a Space Agency, plus we have recently drafted a Space Agency Bill, which commits to research and development in space science.

WHAT ARE THE LIMITATIONS OF EARTH OBSERVATION? Satellite orbits are mostly higher than 500 km, which leads to lower picture resolution (that is, the detail is not as fi ne as it would be in a photograph taken by a plane at 10 kilometres above the ground. In the same way, you’ll see much more detail on the leaf of a plant when you’re standing next to it than you would if you were sitting in a plane or in a satellite that’s outside of the Earth’s atmosphere).

Other drawbacks include the high cost of satellite observation and limitations in instrument sensitivity and the number of species that can be measured.

This is why scientists often combine space and ground-based measurements when trying to understand earth systems.

“SAASTA is a business unit of the National Research Foundation (NRF)

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Space1.indd 3 10/29/08 8:38:00 AM

34

FLOWER POWER Never mind the ‘joys of spring’. Spring’s fl owering grasses and trees can make winter sound more fun. Pollen is airborne, light and small – perfect for inhalation. Since the mucous membrane lining your nose is riddled with the antibodies involved in allergies, you’ll fi nd yourself swabbing a swollen nose before you can even say ‘bless you’. To make matters worse, smooth muscle in your airways contracts, making breathing much harder.

The solution? ‘Avoid or limit exposure to pollen,’ says Dr Sharon Kling of the Allergy Society of South Africa. But if springtime hibernation isn’t your style, antihistamines will help relieve the symptoms. If they don’t work, go for allergy shots to desensitise your immune system to the specifi c allergen.

CREATURE DISCOMFORTS Furry friends really mean trouble if you’re allergic to animals. It’s not the hair that’s the problem, but rather minute amounts of saliva, urine and even dead skin that are stuck to it. Because animal hair easily clings to furniture and carpets, having animals in the house is a no-no. Contact with your eyes can cause them to swell, itch and water, and if hairs land in your nose, you’ll soon start to sneeze.

Matters get worse if you suffer from asthma, as allergens on animal hair can trigger severe asthma attacks. To decrease your risk, use a good vacuum cleaner around the house, and always have an asthma inhaler handy. Antihistamines or nasal sprays can also help. Or just get a fi sh.

They’re in the air. They’re in your bed. They may even be in your lunch. We sniff out the allergies around you.

Allergies.indd 2 10/27/08 4:23:01 PM

MILKY WAYS ‘Food introduces foreign proteins to your body, and you usually grow quite tolerant to them,’ says Dr Harris Steinman, a Cape Town allergy expert. ‘But if your body’s a bit out of balance, the mechanism that drives tolerance isn’t as effective.’

Cow’s milk allergies, especially common in babies, are usually caused by an intolerance of casein and whey proteins, and can cause stomach cramps, vomiting, diarrhoea, skin irritations, a runny nose and a wheezy chest. Not exactly fun.

Most of the world is lactose-intolerant to some degree, but that’s okay because the majority of bad effects are caused only by a lot of lactose. In small doses, milk can still do you good.

on’t you hate the feeling you get when you’re just about to sneeze? Some people have it all the time,

thanks to an immune system disorder called an allergy. This is basically your body’s response to a paranoid immune system that overreacts to seemingly harmless substances.

When faced with an irritant (allergen), your body produces proteins called antibodies, which mark it for destruction. If the same invader trespasses again, your immune system seizes the irritant and triggers a massive release of histamine (another protein), which makes blood vessels widen and smooth muscle contract.

MITEY DUST If you’re allergic to dust, don’t get too excited about avoiding cleaning chores just yet. You don’t actually react to the dust itself, but rather to microscopic beasties called dust mites – and a specifi c protein in their poo. Mites feast on dust that contains fabric fi bres, human skin fl akes and the dead skin that falls off your pets.

They often lurk in feather pillows and bed linen, so it’s a good idea to wash bedding regularly in hot water, and to air your pillows and duvets. As with pollen allergies, antihistamines will help, but if you’re allergic to dust mites only, allergy shots could also keep your immune system calm.

DID YOU KNOW?

The term ‘hay fever’ was fi rst used in the early 19th century, when people began noticing that sniffl es and sneezes increased

during the haying season, especially around freshly

cut hay fi elds.

BODY SMART

YOU’RE ALLERGIC TO WHAT?!

These weird things have triggered allergies:

1 Getting a temporary tattoo Cheap-and-nasty temporary tattoos often contain dyes that are spiked with a synthetic chemical. Some people develop red, swollen rashes that can leave permanent scars. So much for ‘temporary’.

2 Kissing your date About 5% of a group of nut-allergy sufferers said they’d had bad kissing experiences because their dates had eaten nuts before the smooch.

3 Creepy cockroaches A cockroach crawling over some people’s skin can cause a sudden asthma attack, probably triggered by substances found in cockroaches’ poo and saliva.

CLOVER FACT The good news is that a milk allergy is more likely to be outgrown than many other childhood allergies. About 90% of affected children grow out of it by the time they’re four years old.

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B2 diary • Day of Reconciliation 16/12/08 • Christmas day 25/12/08 • New Year 01/01/09

BE THERE –

UNDER THE SEA The Sea World Education Centre

at uShaka Marine World is offering a two-day marine careers

course. Cost: R120, booking essential. • When? 7 and

8 December. • <www.seaworld.org.za/education>

STARS IN THEIR EYES ‘Do the stars infl uence your life?’ That’s exactly what Iziko Planetarium in Cape Town asks in its current show, which explores astrology, how it works and the beliefs surrounding it. • When? Until 30 November. • <www.iziko.org.za>

HIGH SCHOOL MUSICAL We watched locals fi ght for the lead roles of Troy and Gabriella in MNET’s reality show. Now see the winners take centre stage in High School Musical at Cape Town’s Artscape Opera House. To win free tickets to see the show, email <win@hip2b2.com>. • When? From 28 November. • <www.highschoolmusical.co.za>

SURFER GIRLS Whether you’ve never touched a surfboard or

you just need to touch up your skills, the Roxy Learn to Surf tour will

be cruising the eastern coast these holidays, and welcomes all girls.

Booking essential, through Computicket. • When? 6 December ’08

to 7 January ’09 • <www.roxysurfschool.co.za>

007, TAKE 22 Quantum of Solace hits cinemas this

month, as Bond seeks to uncover the truth about Vesper Lynd’s

betrayal. • When? Opens 21 November • <www.007.com>

pp opener.indd 1 10/27/08 4:24:50 PM

WHAT YOU CAN

You don’t think you can dance – you know you can, and now’s your chance to show it.

T

Hip hopBallroom

Latin

• 1ST PRIZE: One month’s free private one-hour Ballroom / Latin lessons for you, your partner and two other couples, courtesy of Quintus Jansen from Strictly Come Dancing.

• 2ND PRIZE: One month’s free 30-minute private dancing lessons for you, your partner and two other couples.

• 3RD PRIZE: One month’s free hip-hop fusion group classes with Quintus Jansen for you and fi ve friends.

• PLUS: 10 hip-hop group classes for you and your partner, with any of the Dance JunXion coaches for one month.

he room is dark. The dance fl oor’s full. Your favourite song has just come on. So what do you do? You get up and dance, and that’s exactly what Dance JunXion wants you to do …

If you love to dance and you’ve got what it takes, email a video clip of yourself in action to <win@hip2b2.com> and fi nd out if you’re the dancer to beat. We’ll load the 30 best clips onto <www.hip2b2.com>, and your family and friends can then log on and vote. Voting runs from 20 November to 31 December 2008.

For more info: Call Dance JunXion (Shop 402, Rosebank Mall, Bath Avenue, Rosebank) on 011 442 6462. Vouchers must be claimed within six months.

COMPETITION

JunXion.indd 1 10/28/08 8:27:23 AM

B2 byte • ‘Music is the strongest form of magic.’ – marilyn manson

MUSIC We tune in to the musical brainwaves of Greg Carlin, frontman for Zebra & Giraff e.

39

THE TING TINGS

We Started NothingWhen I fi rst heard ‘Great DJ’ and ‘That’s not my Name’ on 5FM, I thought they were quirky and fun, but potentially irritating. I have a love–hate response to the album; it has some really cool elements, but also some terrible moments. ‘Keep your Head’ is my favourite song: it has a well-thought-out melody and fun keyboards.Like this? Try Feist, Sara Bareilles and, locally, Tasha Baxter and Stealing Love Jones.

For a taste of Z&G’s hit single, The Knife, click to <www.hip2b2.com>.

GREG REVIEWS ...

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on music, meteorology & Marilyn MansonThe name Zebra & Giraffe doesn’t have any hidden message. I came up with it when we needed a name for the band and it’s quite different, but we received such positive reactions that we’ve stuck with it.If I had to describe myself in three words I would say, ‘Friendly control-freak.’My musical heroes are Nirvana and Dave Grohl, in particular. When he formed the Foo Fighters, I was inspired by the idea of a guitar-playing frontman. At school, I was obsessed with Marilyn Manson and the Goth scene, but more recently I’ve started listening to post-punk indie, like Bloc Party and The Editors. Among my all-time favourite musicians are Chris Isaak and Johnny Cash.Zebra & Giraffe plays alternative electronic-rock, with a smattering of ’80s pop, a heap of indie and undertones of darker industrial elements.I have an honours degree in fi ne art from Tuks, and I’ve always enjoyed designing things. I majored in video and am now getting involved in our music videos. The smartest musicians are Trent Reznor and Radiohead, for their unconventional approach to the changing musical landscape.My favourite school subject was geography. I’m fascinated by weather and climate patterns, and I would have studied meteorology, but I needed science to get in.

THE DIRTY SKIRTS

Daddy Don’t Disco I’d heard a few of their previous singles, but they seem more serious now. They bagged acclaimed muso Theo Crous [of the Springbok Nude Girls] to produce this album and he’s done a great job. The guitar sound and melodies are consistently good. I love the chorus on ‘Daddy Don’t Disco’ and the vocals on ‘T is for Turbo’.Like this? Try Bloc Party, Depeche Mode and The Killers.

pp music1.indd 1 10/27/08 4:26:46 PM

MOVIES Silly Movie Physics Part 3: Fun with the fundamentals of thermodynamics.

40

The laws of thermodynamics* are central to our understanding of the universe. As far as scientists can tell, there are no exceptions. None at all … unless you come from Hollywood,

that is, where many of the world’s most popular movies defy these laws on a regular basis.

A GLITCH IN THE MATRIX

The fi rst rule of thermodynamics is the law of conservation of mass and energy. Basically, it holds that while energy and mass can be transformed, neither can be created or destroyed. The second law – the law of entropy – says energy tends to fl ow from high concentration to dispersion (electrical energy is a concentrated form, while heat is dispersed). In other words, you can never get more than you put in, and a lot of what you do get is just hot air.

Why, then, do the machines in The Matrix try to power themselves using human energy? Not only would it violate the fi rst law of thermodynamics for the machines to get more energy than they put in (to keep the humans alive), but human beings aren’t exactly Energizer Bunnies – we use only about 10% of the energy we consume, with the rest released as heat (there’s that second law in action).

Feeding human beings the remains of other humans isn’t going to help much either – not only are the machines losing energy on each batch, but where does the energy for the fi rst batch come from?

And as for the whole blocking-the-sunlight plan that the people come up with to stop the machines? Don’t they realise that their own food sources depend on photosynthesis by plants? Honestly, sometimes we should think things through before we bite the hand that feeds us.

LIFE IN THE DARK

Many organisms don’t rely on the Sun for energy. Bacteria living around deep-sea vents – underwater volcanoes that spew out scalding water – use the energy of their heated home to make the food they need. They also form the basis for an entire food chain of darkness-dwellers, including clams, crabs and giant tube worms that can be almost three metres long!

*Thermodynamics is the study of the interrelationship of work, heat and energy in a system. (From the Greek therme, heat, and dunamis, power.)

B2 opinion • Things could always be worse ... Plan 9 From Outer Space, made in 1959,

pp movies.indd 2 10/27/08 4:28:45 PM

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SILLY SUPERHEROES

Can’t take superheroes seriously? Don’t miss Superhero Movie, a super-scathing hero spoof on circuit this month.

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None of this makes the slightest difference, of course. Rules, after all, were made to be broken – at least in our fantasies – and they will be, as long as we fi nd it entertaining. And besides, when you live on the silver screen, a little thermodynamic licence never hurt anybody …

THE BIGGEST LAWBREAKER

When Bruce Banner (AKA The Hulk) gets angry – and you wouldn’t like him when he’s angry – he suddenly packs on a whole lot of muscle, exploding from scrawn to brawn in a matter of seconds.

That mass has to come from somewhere, and even his body could get what it needed from the air (the molecules in air aren’t quite the same as those in a human or Hulk body, though), the air is a lot less dense than human tissue (and certainly less than Hulk tissue).

So to double his mass, the Hulk would have to steal all the air for a good few dozen metres around him, making him the centre of a dangerous vacuum. Air would rush in from around him to compensate, and he’d soon be the cause of a rather large whirlwind. And that wouldn’t be good for anyone, really.

SPINNING THE TRUTH

While The Matrix may be the biggest rebel, many other movies refuse to submit to the simple rules of reality. Take Spider-Man, for example. Where exactly does all that webbing come from? Even if each strand were only one centimetre in diameter and 100 metres long (and some of the buildings he swings from are much taller), each swing would eject 0,01 m3 of material, which is around 11% or so of his total body volume (assuming he’s a healthy, 1,7-metre-tall, 70 kg-heavy guy).

A handful of swings and he’d be just a shadow of the man he used to be. And that’s not even taking into account the fact that his webbing’s probably really dense, given its tensile strength, and therefore takes up a lot more mass than Spidey’s volume might lead you to expect.

I’M YOUR SPIDEY-DANCER

Think Spider-Man 3 was a little unsatisfactory? Click to <www.youtube.com/watch?v=HoNgMVFQNBI&feature=user> to see how some people think it should have ended. And while you’re at it, check out the linked Matrix video as well – Hollywood clearly has a lot to learn.

is widely acknowledged as the most hilariously terrible sci-fi movie ever.

pp movies.indd 3 10/27/08 4:29:07 PM

GAMES Around the world, games are moving off the screens and onto the streets. Want to play?

42 B2 diary • World cyber games grand final in germany «www.wcg.com» 05–09/11/'08 BY

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to a treasure cache in your area and start hunting. At their simplest, caches hold a logbook in which you can record your fi nd, but some include all sorts of trinkets, from teddy bears to banknotes. There’s only one rule: anything you fi nd must be replaced with something new for the next lucky hunter.

>> READ AND RELEASE <<In 2004, ‘BookCrossing’ made its debut in the Oxford English Dictionary as ‘the practice of leaving a book in a public place to be picked up and read by others, who then do likewise’. Today, there are 700 000 people worldwide who have read and released over 2 million books.

To become a BookCrosser, register a book on <www.bookcrossing.com> and then release it into the wild for someone to fi nd. Each registered book gets its own BCID (BookCrossing identity) code so you can track its progress around the world.

>> COME OUT AND PLAY <<Although many urban games rely on the Web, anything can be used to create a game. At a recent festival called Come Out and Play in New York, games included Payphone Warriors, in which the aim was to ‘capture’ as many payphones as possible, and Public Space Invaders, which is based on the classic videogame but projected onto the side of a skyscraper, with motion detection sensors allowing players to use their bodies to defl ect the alien invaders.

Also popular are Pillow Fight clubs, which use SMSs to tell people where and when the next fi ght will occur. At the appointed time, a crowd of pillow-armed people converge, much to the confusion of innocent bystanders.

In London, a crowd of people are attacking one another with pillows. In Tokyo, several people are searching for hidden treasure, and in Johannesburg, a girl has just captured a wild book. No, they aren’t crazy; they’re just urban gamers.

Urban games come in many forms, but they all have three things in common: they use technology like cellphones, GPS and the Internet; they take place in large spaces (think the whole city); and they require a hefty dose of imagination.

>> Urban pirates <<Ever wanted to hunt for hidden treasure? Here’s your chance. Geocaching (pronounced geo-cashing) is a game that uses the Internet and GPS technology to create a modern-day treasure hunt. To play, all you need is a GPS and access to <www.geocaching.com>. Log on, download the map (GPS coordinates)

JOIN THE REVOLUTION Urban games are already in SA. Geocaches exist across the country, and books roam wild in Joburg and Cape Town. So whether you see yourself as a BookCrosser, a Geocacher or the creator of a whole new game, just remember: the world is your playground.

pp games.indd 1 10/27/08 4:29:47 PM

OGO NKADO

Grade 10, Northcliff High School, Joburg

I found this book very interesting and informative, and thanks to the author’s quirky comments, it also made me chuckle.

The book aims to highlight the presence of science all around us, and to point out that it’s possible for you to answer scientifi c questions in the comfort of your own home.

The coolest thing I learnt is that hot water freezes faster than cold water.

My favourite experiment is the one in which you heat an egg over a candle until the egg goes black, then put it into water. The egg’s colour changes from black to silver.

I always thought that smacking a tomato ketchup bottle on its bottom was the best way to get out the last globs of sauce. Completely wrong! It actually sends the sauce right back to its base – which, if you think about it, really makes a lot of sense.

Mick O’Hare and New Scientist magazine celebrate the timeless quest to question in How to Fossilise Your Hamster (London: Profi le Books Limited 2007), a crazy collection of experiments that’ll teach you how to weigh your own head, make plastic out of milk and vinegar and, of course, how to fossilise your favourite furry friend.

QUICK QUOTE ‘If you really want your pet to survive the ravages of geological time, then while it is still alive you need to concentrate on improving the quality of its teeth and bones … If [it] has eaten a few seeds in its last days, these too can become fossilised and intrigue palaeontologists in the millennia to come.’

Would you like to review a book for us? Write to: HIP2B2 Book Reviews, PO Box 440, Green Point 8051 or email: <talk2us@hip2b2.com>. Please include your name, contact details, address, school and grade.44

BOOKS How to Fossilise Your Hamster

JEREMY LAI HONG

Grade 10, Northcliff High School, Joburg

The coolest thing I learnt from this book was that you can calculate the speed of light using a chocolate bar and microwaves. [We also loved this experiment, Jeremy! In fact, we featured it in the Why Issue (Feb ‘08). – Janna]

My favourite experiment is Mixing Madness, because it is fun to play with and delivers an unexpected result. It seems as though the liquid anticipates the rate at which you will stir it.

I still have some questions I’d like to see answered if they put out another book like this. First, I’ve heard it’s possible for four people to lift someone heavier than themselves, each using only one fi nger. Can this be true? Also, is there a way to get negative matter by replicating the effects of a black hole?

IF YOU LIKED THIS, CHECK OUT ...

Quirkology: The curious science of everyday lives by Richard Wiseman (London: Pan Macmillan 2007). This is a fun look at when and why people lie, the scientifi c search for the funniest joke in the world, and how to fi nd ghosts using infrasound.

Why Don’t Penguins’ Feet Freeze? by New Scientist (London: Free Press 2007). Want to know why superglue doesn’t stick to the inside of the tube, why our knuckles make that popping sound when we crack them, and how to measure time at the North Pole? Then you’ll love this quirky collection of 115 expert answers to reader questions from New Scientist magazine.

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pp books.indd 1 10/27/08 4:31:01 PM

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SUDOKU WHEEL WORD WHEEL

ANSWERS

WHO’S PLAYIN’ WHOM?

HIGHWAY WHEEL COUNT

Each of the three rings must contain the numbers 1 to 9. Adjacent numbers in a ring cannot be consecutive (for example, 3 cannot go next to 4 or 2) and, similarly, the three numbers in each sector (or slice) of the wheel cannot be the same or consecutive numbers (for example, if 5 appears in a sector, then 4, 5 or 6 cannot be present in the other two positions). The green areas represent all the even numbers, while red represents the odd numbers.

On a busy Monday morning, a section of highway near a city is experiencing some heavy traffi c with cars, six-wheel trucks and motorbikes. In a 20-metre section of the highway there are 16 vehicles in total. There are four times as many cars as motorbikes, and three times as many trucks as motorbikes.

The number of motorbikes is the same as the difference between the number of cars and trucks, and one type of vehicle makes up half of the total number of vehicles. How many wheels in total are there on this 20-metre stretch of highway?

In the right order, these letters spell out a nine-letter word that can mean either ‘a sporty, convertible car’ or ‘a two-wheeled horse-drawn carriage’. What is the word? While you’re at it, see how many other words of four letters or more you can fi nd (we found 46).

Four Premier League soccer matches are to be played tonight. Three sports journalists predict the four winning teams. One predicts Sundowns, Jomo Cosmos, Ajax Cape Town and Chiefs will win. Another predicts Pirates, Swallows, Ajax Cape Town and Sundowns will be the winners. The third journalist favours the chances of Bloemfontein Celtic, Jomo Cosmos, Swallows and Sundowns. No-one picks Platinum Stars. Who is playing against whom in each of the four matches?

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72 wheels (8 cars, 6 trucks and 2 motorbikes).

WORD WHEEL

Cabriolet.

WHO’S PLAYIN’ WHOM?

Sundowns vs Platinum Stars.Jomo Cosmos vs Pirates.Ajax Cape Town vs Bloem Celtic.Chiefs vs Swallows.

SUDOKU WHEEL

brainbuster.indd 1brainbuster.indd 1 10/28/08 8:05:06 AM10/28/08 8:05:06 AM

So, Agent 002, you now have all the info you need to understand space science. From now on, your voyage can truly begin. To start you off , here’s a little more about the out-of-this-world fi eld you’re entering, and the work you can do using space science.

SOME QUESTIONS ADDRESSED BY SPACE SCIENCE • CHANGING ICE SHEETS AND SEA

LEVEL Will the major ice sheets, such as those of Greenland or the West Antarctic, collapse? If they do, how quickly will this happen and how fast will the sea level rise?

• LARGE-SCALE SHIFTS IN RAINFALL AND WATER AVAILABILITY Will we have more droughts in specifi c places? How will this aff ect wildfi res and will a decrease in snowfalls change the way we store water?

• AIR POLLUTION ACROSS CONTINENTS How will ongoing economic development aff ect the production of air pollutants, and how will these pollutants move across oceans and continents?

• EFFECTS OF CLIMATE CHANGE ON ECOSYSTEMS How will coastal and ocean ecosystems respond to changes in the climate, particularly those systems with a lot of human activity, such as fi shing? If temperature and rainfall

changes, how will this impact on animal migration patterns?

• HUMAN HEALTH AND CLIMATE CHANGE Will previously rare diseases become common? How will mosquito-borne viruses spread with changes in rainfall and drought?

• EXTREME EVENTS, INCLUDING SEVERE STORMS, HEAT WAVES, EARTHQUAKES AND ERUPTIONS Will tropical cyclones and heat waves become more frequent and intense?

RESEARCH AND DEVELOPMENT IN SPACE SCIENCE AND ITS APPLICATIONS Billions of dollars have been invested in the development of space science projects. Apart from the USA, many countries are involved in space research, including Russia, China, Japan, India, Pakistan, Australia, South Africa, Nigeria and Brazil. New developments in space research will lead to satellites that are able to measure:• solar and Earth radiation;• soil moisture and freeze-thaw for weather and water cycle processes;

• ice sheet height changes for the eff ects of climate change;

• make-up of land surface for agricultural and mineral classifi cation; and

• atmospheric gas columns for air quality forecasts.

SPACE SCIENCE CAREERS Space science is very broad and includes a number of fi elds that seem unrelated. Careers include space geodesy (determining the position of geographical points, as well as the shape and size of Earth), aeronautics, orbital dynamics, satellite technology, oceanography, land management, mapping, forestry, agriculture and GIS (geographical information systems).

All of these can be split into fi elds of specialisation. Anybody with post-school training in mathematics, physics, electronics, engineering, geology, geophysics, geography, computer science, statistics or nearly any related subject will be able to pursue a career in space science.

ADVERTORIAL

“SAASTA is a business unit of the National Research Foundation (NRF)

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Space1.indd 4 10/28/08 9:39:41 AM

SIMPLY SCIENCE

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WHAT REALLY HAPPENS WHEN ...

Ice cream is one of life’s little pleasures. But be warned: eat it wrong and you may fi nd yourself with a nasty headache.

Ice-cream headaches tend not to last long, thankfully – 30 seconds or so and it’s all over. But that’s 30 seconds you’d probably be a whole lot happier without. And some people are even unlucky enough to have brain freezes that trigger more serious migraines.

So what’s going on here?Ironically, brain freeze is caused by a process designed to prevent your brain from freezing. When something cold touches the roof of your mouth on a hot day, it causes blood vessels in your head to constrict. This response is thought to be triggered by a nerve centre located just above the roof of your mouth.

When this nerve centre senses extreme cold, it tries to keep your brain warm by backing the blood up inside your head. The problem is, while your brain may be toasty, the rest of your head starts to ache under the increased pressure.

Fight the freeze You can speed up recovery by pressing your tongue hard against the roof of your mouth, or by drinking something warmer than the ice cream. But it’s probably best just to avoid the dreaded brain freeze by keeping cold things away from the roof of your mouth, at least on those lovely summer days.

YOU GET ICE-CREAM BRAIN FREEZE

FAST FACT The ice-cream age

Ice cream’s been around for a very long time. In thefi rst century BCE, Roman Emperor Nero enjoyed a frozen dessert made of snow, nectar, fruit pulp and honey.

simply science.indd 1 10/28/08 8:07:17 AM